Up until 1959, Computers had been incredibly expensive because they required so much hand assembly, as seen below.
Typical wiring in an early mainframe computer (photo courtesy The Computer Museum)
The microelectronics revolution is what allowed the amount of hand-crafted wiring seen in the prior photo to be mass-produced as an integrated circuit which is a small sliver of silicon the size of your thumbnail .
The primary advantage of an integrated circuit is not that the transistors (switches) are miniscule (that's the secondary advantage), but rather that millions of transistors can be created and interconnected in a mass-production process. This speeds up the process of fabricating the computer -- and hence reduces its cost -- just as Gutenberg's printing press sped up the fabrication of books and thereby made them affordable to all.
University students in the 1970's bought blank cards a linear foot at a time from the university bookstore. Each card could hold only 1 program statement. To submit your program to the mainframe, you placed your stack of hole-punched cards in the hopper of a card reader. Your program would be run whenever the computer made it that far. You often submitted your deck and then went to dinner or to bed and came back later hoping to see a successful printout showing your results. Obviously, a program run in batch mode could not be interactive.
But things changed fast. By the 1990's a university student would typically own his own computer and have exclusive use of it in his dorm room.
The original IBM Personal Computer (PC)
This transformation was a result of the invention of the microprocessor. A microprocessor (uP) is a computer that is fabricated on an integrated circuit (IC). Computers had been around for 20 years before the first microprocessor was developed at Intel in 1971. The micro in the name microprocessor refers to the physical size. Intel didn't invent the electronic computer. But they were the first to succeed in cramming an entire computer on a single chip (IC).
The Move to Microprocessors
Up until 1959, Computers had been incredibly expensive because they required so much hand assembly, as seen below.
The microelectronics revolution is what allowed the amount of hand-crafted wiring seen in the prior photo to be mass-produced as an integrated circuit which is a small sliver of silicon the size of your thumbnail .
The primary advantage of an integrated circuit is not that the transistors (switches) are miniscule (that's the secondary advantage), but rather that millions of transistors can be created and interconnected in a mass-production process. This speeds up the process of fabricating the computer -- and hence reduces its cost -- just as Gutenberg's printing press sped up the fabrication of books and thereby made them affordable to all.
University students in the 1970's bought blank cards a linear foot at a time from the university bookstore. Each card could hold only 1 program statement. To submit your program to the mainframe, you placed your stack of hole-punched cards in the hopper of a card reader. Your program would be run whenever the computer made it that far. You often submitted your deck and then went to dinner or to bed and came back later hoping to see a successful printout showing your results. Obviously, a program run in batch mode could not be interactive.
But things changed fast. By the 1990's a university student would typically own his own computer and have exclusive use of it in his dorm room.
This transformation was a result of the invention of the microprocessor. A microprocessor (uP) is a computer that is fabricated on an integrated circuit (IC). Computers had been around for 20 years before the first microprocessor was developed at Intel in 1971. The micro in the name microprocessor refers to the physical size. Intel didn't invent the electronic computer. But they were the first to succeed in cramming an entire computer on a single chip (IC).Back to the Homepage
References:
Kopplin, John. (2002) An illustrated history of computers. Accessed from http://www.computersciencelab.com/ComputerHistory/HistoryPt4.htm